Quantitative analysis of the benzanthrone aminoderivative binding to amyloid fibrils of lysozyme

The accumulation of amyloid fibrils in different tissues is associated with a number of neurodegenerative diseases. Despite a huge variety of amyloid-specific probes, all of them suffer from many drawbacks, highlighting the necessity of searching for more preferable dyes. In the present work, the potential of new fluorescent probe AM3 for selective detection of fibrillar protein aggregates, formed from lysozyme, has been evaluated. To quantify the affinity of this dye for amyloid fibrils, the isotherms of dye binding to the fibrillar lysozyme have been derived from fluorimetric titration. Parameters of the dye-protein complexation: association constant, molar fluorescence and binding stoichiometry, calculated from the Langmuir adsorption model, revealed that AM3 interacts strongly with protein insoluble aggregates. High values of the binding parameters make AM3 an alternative to a widely-used amyloid-specific probe Thioflavin T. We also investigated the effects of polarity and viscosity on AM3 fluorescence properties. The binding of AM3 to the protein hydrophobic cavities has been followed by red shift of the dye emission spectra, which can be explained by H-bonding between proton-donating groups of the protein and carbonyl moiety of the probe. Long-wavelength shift of emission maximum was observed also upon increasing the excitation wavelength. This finding suggests that reorientation time of solvent molecules is higher, than the dye fluorescence lifetime. Fluorescence anisotropy studies revealed slow rotation diffusion of the probe, bound to amyloid fibrils being indicative of high viscosity of AM3 microenvironment. The observed photophysical properties of the new aminobenzanthrone derivative make AM3 a perspective probe for basic research and medical diagnostics

Floral complexes with the involvement of Adonis Vernalis L. (fam. Ranunculaceae juss.) and environmental assessment of the conditions of their formation in the Southwest of Central-Russian Upland

The article presents the results of the study of structures of floral complexes with the involvement of Adonis vernalis L., the number of genera, families and species is indicated. Average points of severity of environmental factors were calculated, allowing assessing the environmental conditions in these ecotopes. Ecobiomorphs of species of the floral complexes in natural and quasi-natural ecotops are determine

Mutants of Taq DNA polymerase resistant to PCR inhibitors allow DNA amplification from whole blood and crude soil samples

Potent PCR inhibitors in blood and soil samples can cause false negative results from PCR-based clinical and forensic tests. We show that the effect of these inhibitors is primarily upon Taq DNA polymerase, since mutational alteration of the polymerase can overcome the inhibition to the extent that no DNA purification is now required. An N-terminal deletion (Klentaq1) is some 10–100-fold inhibition resistant to whole blood compared to full-length, wild-type (w.t.) Taq, which is strongly inhibited by 0.1–1% blood. Further mutations at codon 708, both in Klentaq 1 and Taq, confer enhanced resistance to various inhibitors of PCR reactions, including whole blood, plasma, hemoglobin, lactoferrin, serum IgG, soil extracts and humic acid, as well as high concentrations of intercalating dyes. Blood PCR inhibitors can predominantly reduce the DNA extension speed of the w.t. Taq polymerase as compared to the mutant enzymes. Single-copy human genomic targets are readily amplified from whole blood or crude soil extract, without pretreatment to purify the template DNA, and the allowed increase in dye concentration overcomes fluorescence background and quenching in real-time PCR of blood

Use of settlement indexes for an assessment of physical development of preschool children of the city of Irkutsk

189 children of preschool age of 3-6 years of the city of Irkutsk are examined. The assessment of FR of children by means of a method of indexes, showed discrepancy of calculations by this method with groups of a harmony of FR of the preschool children examined by method the tsentilnykh of tablesОбследовано 189 детей дошкольного возраста 3-6 лет города Иркутска. Результаты исследования выявили увеличение массы тела дошкольников. Оценка ФР детей с помощью метода индексов, показала несоответствие расчетов данным методом с группами гармоничности ФР дошкольников, обследованных методом центильных табли

Functioning of information educational environment: Meta dynamic approach

© 2015 by the authors. The article substantiates the meta dynamic approach that determines ways for information educational environment analysis. The implementation of the said approach includes a versatile analysis of information with the application of offered meta dynamic methods and tools. Tools of meta dynamics allow to regard changes in the rate of the information process, to analyze structural modifications of the information environment. The change of the information process can be analyzed, for example, if the rate of new information emegence and the rate of its processing are taken into account. These and other similar measuring instruments are based on indicators of the second order. The modification of the information structure is analyzed on the basis of absolute and relative indexes of the moved and changeable information volume, and the dynamics of the environment structure. There the process of information restructuring is implied, including, for example, the emergence of new structural components, their association, removal, specification. In this context there has been given a theoretical justification for the set of meta dynamic tools of the second order application. There have been presented some results of their experimental approbation. The significance of the designated approach has a predictive value in the development of a vocational school and its information educational environment

Peculiarities of physical development of preschool children in Irkutsk

The article describes the assessment of the physical development (PD) of the children attending preschool educational institution kindergarten N 148 of Irkutsk. It was established that different types of deviations in development had 42.0 % of children from 3 to 7 years. Among deviations in PD of preschool children most frequently we noted high body weight at normal body length (10.1 %); also lowered (8.0 %) and low body length (9.0 %) were established. The results of the examination of Irkutsk preschool children revealed deviations of their PD parameters from normal figures towards reduction of growth and increase in body weight, and also showed that morphometric changes were more characteristic of boys

Interaction of novel benzanthrone derivative with amyloid lysozyme

A novel benzanthrone derivative AM18 was investigated with respect to its photophysical properties when bound to native, oligomeric and fibrillar hen egg white lysozyme. As shown by fluorimetric titration AM18 is more sensitive to pathogenic protein aggregates than Thioflavin T, however has no ability to differentiate between mature and immature lysozyme fibrils. The recovered affinity and fluorescence response of the novel probe to amyloid protein appeared to be similar to those of recently developed amyloid lysozyme-sensitive dyes like e. g. Nile Red and cyanine dye 7515. Despite the high increase of the probe emission in the presence of amyloid lysozyme compared to its fluorescence in buffer, the minimal amount that could be detected by 1 μM AM18 was 10 times lower for amyloid-native protein solutions due to high affinity of the dye for lysozyme monomers. In general, because of high quantum yields and “signal-to-noise” ratios in the presence of pathogenic protein aggregates AM18 appeared to be an effective tool for amyloid detection and characterization in vitro, being however unable to detect pathogenic protein aggregates in vivo like e.g. recently reported p-FTAA because of the sensitivity to lipids. Compared to previously reported AM3 a novel dye showed 2-fold lower “signal-to- noise” ratio in the presence of fibrillar lysozyme, and 2 fold lower blue shift of emission maximum. This tendency was explained in terms of decreased charge transfer from the donor to acceptor groupes of AM18 compared to AM3. Finally, as concluded from the comparison of AM18 and previously studied benzanthrone derivatives, the 5 nm – red edge excitation shift of AM18 is indicative of its possible binding to fibril “deep cavities”, containing no water. High anisotropy values of amyloid-bound dye led us to conclusion that the enhanced fluorescence of the probe is associated with the decrease of the rotational motion of the amino-substitute about the benzanthrone unit. This is a sign of AM18 behaviour as a molecular rotor